Tunnel kiln



ATTORNEY Oct. 5 1926.

L. A. VINCENT TUNNEL KILN Filed June 28, 1925 oooo oooo ooooo\ Patented Qct. 5, 1926.

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LAURENCE ARTHUR VINCENT, or rLEAsAN'rvILLE, PENNSYLVANIA, AssiGNon 'ro AMER/TLCAN DRESSLER TUNNEL KILNS, TON 0F NEW YORK.

.Application led .Tune 28, 1923.

My present invention relates tocontinuous tunnel kilns of the munie type, and more particularly to kilns of the lDressler type,

which are `heated by combustion chambers which are located at the sides of the goods pathwayV and formed with channels vin their walls for setting up al directed convection current circulationoi theV kiln atmosphere, whereby heat is transferred from thecombustion chambers to the; of the combustion cha against overheating; .an of my invention. is

goods, and the walls mber are protected d'the general object to provide improvements tending to a better circulation ot the rkiln atmosphere.

The various features oi novelty which characterize my invention are pointed out with particularity in'th e claims annexed to and forming a part 'of this specification. For a better understanding' oi: the invention,

however, and its should be had to the ments ot my invention.

Ot'the drawings;

advantages,

accompanying drawings and descriptive matter in which I have l illustrated and described' preferred embodlreference Eig. l is a somewhat diagrammatic sectional plan;

Eig. 2 is a transverse section'on the line Eig, 8 is a transverse section on the line' communicatethrough'ports GS-and a flue the line Yt--l 'of 3-3 oit Eig. lg-and Eig. 4 is a section on Eig. '1.

ln the drawings, chamber riding benches sions E thereot1 at the entrance end. of the kiln, and the air cooling pipes G adjacent the exit end of the kiln. bustion chambers each through one or more each receives air for burner l the combustion of theV As shown the comreceive fuel vas gas nozzles H', and

fuel directly Jtrom the kiln chamber `through ports HA. The airpass tion chamber may enter the kiln Ychamber through lports A10 .at

inginto the combusthe exit end Vof the kiln and this air,supplements-thekiln cooling eii'ect ofthe pipes G. Y

the'exitjdoor ofthe ports A10. .are formed in As shown the The various sections Yand at the upper ends ort the sections 'In operation the kiln atmosphere in the Vthrough the ports G', airrout of the pipes INC., OF'CLEVELAND, OHIO, A CORPORA- i TUNNEL KILN.

Serial No. 648,199.

conduit'l, by a suitable draft creating device shown as a stack J. The walls ot each combustion chamber are formed or" hollow tile sections E, E', E2 and E3, each ot which tentends transversely to the length of the kiln chamber, and each of which is Y.termed with a Vplurality of longitudinal channels e. E, E, E2 and E3, which are formed of refractory Amaterial as lire clay or carborunduin, are shaped to ht together as shown in Eig. 2so that the channels c Iin thevarious tiie sections E, E', E2 and Ef unite to vtorni tlues open to the kiln chainbers at the ends of the bottom sections E E3.

channels e is heated above Vthe average kiln atmospheretemperature in the adjacent portions of the kiln chamber and this creates a Aconvection current circulation of the kiln `atmosphere as indicated by the arrows in Eig.- with the atmosphere'at the exit end ot the V- kilnfthrough ports G" and adjacent the coinbustion' chambers 2- 'The Cooling pipes G communicate D. The pipes VG are connectedy to' headers or end chambers G2 which G4E with*v a suitable draft creating device (not shown) forv1 drawing air into the pipes G and i`or drawing this G through Vthe headers AG, ports'G3 and flue Gt. qinsofar above described the kiln illustrated contains nothing novel witli-mc, but on the contrary is a wellQknown form of Dressler kiln in extensive use.

The combustion chambers illustrated.diier from those heretofore employed in two respects.` One ofJ these ditierences arises from the fa'ctifthat I make `the vertical depth of each channel@ in the horizontal bottom tile sections-E Vand preferably also in the top section E3, substantially lgreater than the corresponding dimension ci the channels c inthe side. tile sections E and E2, whereas fit has heretofore been Vthe practice tov make all of' the/tile' ysections employed in par cia ticular combination chamber exactly similar in transverse section dimensions. lhile the invention, of course, is not limited to any ef-:act dimension or proportion, it may facilitate an understendingI of the invention to point out that in ordinary kilns I propose to ineke the vertical depth of the channels in the sections E and 8 inches,rand to make the corresponding dimensions of the channels c in each of the sections E and E2, G inches.

rlie second difference between the combustion chambers illustrated, and those heretofore employed, is found in the fact that the bottoni tile sections E project into the kiln chamber past the lower ends of the inner side sections E, and past the inner sides of the corresponding benches B, into grooves C formed in the sides of the cars beneath the goods supporting platform C2 of the ars and in close proximity to the ends of the transverse circulation channels C3 formed in the wall portions of the car bodies immediately beneath the platforms C2 which are usually perforated to permit the circulation of the kiln atmosphere down through the goods K on the car platforms into the tops of the channels C3.

The above noted differences between the combustion chamber construction and arrangement disclosed, and the practice heretofore followed, each contribute to a more int-ense and better distributed kiln atmosphere circulation. In particular the greater depth of the channels e in the bottom and top sections E and E3 tend to increase the upflow through the channels e in the outer sections E2, yand more nearly equal to the uplow through the channels e in the sections E than has been the case with the constructions heretofore employed, thus improving the heat transfer and avoiding a sometimes 'undesirable tendency for the outer wall sections E2 of the combustion chamber to become appreciably hotter than its inner wall sections E.

'Ihe extension of the inner ends of the bottom sections E under the side edges of the car platforms and in close proximity to the channels G3, also tends to a more vigorous Acirculation of the kiln atmosphere and a better distribution of the descending current of the kiln atmosphere through the portion of the kiln chamber traversed by the goods.

rIhe kiln illustrated also differs from kilns of the same general type heretofore employed, in that provisions are made for withdrawing a portion of the kiln atmosphere from the kiln chamber adjacent the entrance end of the latter and at approximately the level of the bottom of the goods pathway.,

The provisions shown for this purpose comprise ports K and KA. The ports K open at the tops of the benches B adjacent their inner edges and are connected through a conduit K to the stack J. The ports KA open from the antechamber A20 of the kiln at about the level of the tops of the benches B into vertical channels K5 which are connected through a conduit K6 to the stack J. The conduits K and KG are each provided with a damper K2. In practice air may be withdrawn from the kiln chamber exclusively through the ports K, or exclusively through the ports KA, or partly through the ports K and partly through the ports KA, as conditions make desirable. The withdrawal of a small quantity of the kiln atmosphere through ports located as are the ports K and KA is desirable in any form of mufle kiln in which a draft suction is impressed on a central portion of the kiln chamber, such as is impressed in the kiln illustrated, by the ports HA through which the combustion chambers D are supplied with air for combustion from the kiln chamber. rIhewithdrawal of the kiln atmosphere from the exit end of a muflle heated kiln. tends to eliminate an otherwise objectionable longitudinal circulation in the kiln chamber which is generally undesirable and i'n the case of the Dressler type of kiln illustrated isespecially objectionable, as it interferes with the desired transverse circulation through the channels e in the walls of the combustion chambers. This feature of my invention is especially advantageous in the case of a kiln employed in burning bricks or other coarse clay products as it draws out of the kiln chamber a good deal of the steam or watersmoke driven out of the goods in their initial heating up, and prevents the steam or watersmoke passing into the high temperature portion of the kiln chamber. The elimination of steam or water-smoke in this manner tends to reduce the fuel consumption of the kiln, and makes it easier to hold the heat, and tends to a better firing of the lower portions of the masses of goods stacked on the cars.

While in accordance with the provisions of the statutes, I have illustrated and described the best forms of my invention now known to me, it will be apparent to those skilled in the art that many changes may be made in the form of the apparatus disclosed without departing from the spirit of my invention as set forth in the appended claims, and that certain features of my invention may sometimes be used with advantage without a corresponding use of other features.

Having now described'my invention, what I claim as new and desire to secure by Letters Patent, is:

l( In a continuous tunnel kiln provided with closed combustion chambers at the sides of the goods pathway through the kiln, from which heat is transferred to the ware passing through the kiln mainly by aV transverse convection circulation of the kiln atmosphere, the improvement Which consists in means for exerting a kiln atmosphere eX- hausting effect at the Ware entrance end of the kiln adjacent the bottom level of the goods pathway therethrough.

2. ln a continuous tunnel kiln the combination with goods carrying cars formed with goods supporting platforms projecting at the sides of the cars beyond the subjacent portions ot' the cars and also formed With transverse channels having open ends at the sides of the cars below said platforms 'and communicating through the platforms With the space above the latter, and combustion chambers at the sides of the cars, the bottom Walls of which are formed by tile sections transverse to the length of the kiln With their inner ends extending under the projecting edges of the car platforms and provided lWith longitudinally extending open ended channels and other tile sections forming the upper portions of the Walls of the combustion chambers and formed with channels uniting With the channels in the bottom tile sections to form a kiln chamber through the channels in the bottom section and at the top of the combustion chambers.

3. In a. tunnel kiln having muiiie heating provisions comprising means for exerting a kiln atmosphere exhausting eiect in a high temperature portion of the kiln chamber, the improvement which consists in means for exerting a second kiln atmosphere exhausting eiiect at the Ware entrance of the kiln adjacent the bottom level of the goods path- Way therethrough.

Signed at Cleveland, Cuyahoga and State of Ohio, of June, A. D., 1923.

LAURENCE ARTHUR VINCENT.

in the county of this 23rd day flue system open to the 

